and now i need to show the other side is equal to 2/3sin(pi/4) right? i.e
could you give me a hint on how to integrate this one please. thanks mate.

Aug 7th 2007, 06:39 PM

smoothman

lol cheers. you've done the working for me joanne. i was acutally about to post the same question i.e. how do you show the left hand formula to be equal to 2/3sin(pi/4)

Aug 7th 2007, 06:52 PM

ThePerfectHacker

Quote:

Originally Posted by smoothman

lol cheers. you've done the working for me joanne. i was acutally about to post the same question i.e. how do you show the left hand formula to be equal to 2/3sin(pi/4)

You need to use three different line integrals.

Aug 8th 2007, 05:37 AM

smoothman

cool thanks. ill work out the line integrals now.

was my answer correct though?
so now i have to work out that the line integrals also add up to my answer? correct?

Aug 8th 2007, 12:59 PM

smoothman

here is what i managed to work out so far for the line integrals:

i know since P=xy and Q=x^2

for r1(t)

so:

+

= +

= +

=

for r2(t)

i got:

SO THE LINE INTEGRALS OF r1(t) and r2(t) cancel each other out.

for r3(t)... This is where im having problems

+

but i cant seem to do any more of it.. stuck here.. how do i complete it
.................................................. .....
ok the questions:
(a) were my line integrals of r1 and r2 correct
(b) what is the answer of r3
(c) is the final answer of these line integrals